In a drum brake assembly a pair of brake shoes is urged into engagement with a drum to retard the rotation of the latter. A hydraulic actuator slidably carries a piston which abuts at least one of the pair of brake shoes and the piston is responsive to increases in pressure within the hydraulic actuator to move relative thereto, thereby moving the brake shoe into engagement with the drum.
This piston rests on a stop on the hydraulic actuator so that upon pressurization of the hydraulic actuator the piston moves away from the stop to urge the brake shoe into braking engagement with the drum. When contact between the drum and brake shoe is initially achieved, the pair of brake shoes frictionally grip the rotating drum and the pair of brake shoes is rotated slightly in the direction of rotation of the drum until one of the brake shoes abuts the stop. Further pressurization of the hydraulic actuator at this time increases the braking forces between the pair of brake shoes and the drum to retard the rotation of the drum.
When the one brake shoe abuts the hydraulic actuator stop upon initial contact between the pair of brake shoes and the drum a clunking noise occurs as the impact between the stop and the piston can be quite large. Consequently, elimination of this clunking noise by simple means without interfering with brake bleeding or imposing a delay on normal brake application rates is believed to be an improvement over the state of the art.